In the related art, controlling a robot with robot vision has required a process of calibrating a robot coordinate system and a coordinate system of a capturing unit. During calibration, the position of a reference point in a space where a robot is installed is specified in each of the robot coordinate system and the coordinate system of the capturing unit, and a matrix for transforming the position of the reference point represented in one coordinate system into the position of the reference point represented in the other coordinate system is obtained. According to the technology disclosed in JP-A-8-210816, calibration is performed by teaching reference points in the robot coordinate system by moving an arm to touch three reference points and then by capturing markers that indicate the reference points with the capturing unit that is moved by the arm to a predetermined position and by detecting the reference points in the coordinate system of the capturing unit.
According to the technology disclosed in JP-A-8-210816, teaching the positions of the reference points is required by an operation of the arm by an operator to touch the three reference points. However, it is not easy to accurately operate the arm while visually specifying whether the arm touches the reference points or not. That is, the technology disclosed in JP-A-8-210816 has a problem in that it is not easy to accurately teach the positions of the reference points. Another problem arises in that a necessary time required for calibration is prolonged when calibration is performed with accurate teaching of the positions of the plurality of reference points. As the number of calibration target robots increases, this problem becomes worse.